Markdown parser, done right. 100% CommonMark support, extensions, syntax plugins & high speed https://markdown-it.github.io/
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

353 lines
8.4 KiB

/**
* class Ruler
*
* Helper class, used by [[MarkdownIt#core]], [[MarkdownIt#block]] and
* [[MarkdownIt#inline]] to manage sequences of functions (rules):
*
* - keep rules in defined order
* - assign the name to each rule
* - enable/disable rules
* - add/replace rules
* - allow assign rules to additional named chains (in the same)
* - cacheing lists of active rules
*
* You will not need use this class directly until write plugins. For simple
* rules control use [[MarkdownIt.disable]], [[MarkdownIt.enable]] and
* [[MarkdownIt.use]].
**/
'use strict';
/**
* new Ruler()
**/
function Ruler() {
// List of added rules. Each element is:
//
// {
// name: XXX,
// enabled: Boolean,
// fn: Function(),
// alt: [ name2, name3 ]
// }
//
this.__rules__ = [];
// Cached rule chains.
//
// First level - chain name, '' for default.
// Second level - diginal anchor for fast filtering by charcodes.
//
this.__cache__ = null;
}
////////////////////////////////////////////////////////////////////////////////
// Helper methods, should not be used directly
// Find rule index by name
//
Ruler.prototype.__find__ = function (name) {
for (var i = 0; i < this.__rules__.length; i++) {
if (this.__rules__[i].name === name) {
return i;
}
}
return -1;
};
// Build rules lookup cache
//
Ruler.prototype.__compile__ = function () {
var self = this;
var chains = [ '' ];
// collect unique names
self.__rules__.forEach(function (rule) {
if (!rule.enabled) { return; }
rule.alt.forEach(function (altName) {
if (chains.indexOf(altName) < 0) {
chains.push(altName);
}
});
});
self.__cache__ = {};
chains.forEach(function (chain) {
self.__cache__[chain] = [];
self.__rules__.forEach(function (rule) {
if (!rule.enabled) { return; }
if (chain && rule.alt.indexOf(chain) < 0) { return; }
self.__cache__[chain].push(rule.fn);
});
});
};
/**
* Ruler.at(name, fn [, options])
* - name (String): rule name to replace.
* - fn (Function): new rule function.
* - options (Object): new rule options (not mandatory).
*
* Replace rule by name with new function & options. Throws error if name not
* found.
*
* ##### Options:
*
* - __alt__ - array with names of "alternate" chains.
*
* ##### Example
*
* Replace existing typorgapher replacement rule with new one:
*
* ```javascript
* var md = require('markdown-it')();
*
* md.core.ruler.at('replacements', function replace(state) {
* //...
* });
* ```
**/
Ruler.prototype.at = function (name, fn, options) {
var index = this.__find__(name);
var opt = options || {};
if (index === -1) { throw new Error('Parser rule not found: ' + name); }
this.__rules__[index].fn = fn;
this.__rules__[index].alt = opt.alt || [];
this.__cache__ = null;
};
/**
* Ruler.before(beforeName, ruleName, fn [, options])
* - beforeName (String): new rule will be added before this one.
* - ruleName (String): name of added rule.
* - fn (Function): rule function.
* - options (Object): rule options (not mandatory).
*
* Add new rule to chain before one with given name. See also
* [[Ruler.after]], [[Ruler.push]].
*
* ##### Options:
*
* - __alt__ - array with names of "alternate" chains.
*
* ##### Example
*
* ```javascript
* var md = require('markdown-it')();
*
* md.block.ruler.before('paragraph', 'my_rule', function replace(state) {
* //...
* });
* ```
**/
Ruler.prototype.before = function (beforeName, ruleName, fn, options) {
var index = this.__find__(beforeName);
var opt = options || {};
if (index === -1) { throw new Error('Parser rule not found: ' + beforeName); }
this.__rules__.splice(index, 0, {
name: ruleName,
enabled: true,
fn: fn,
alt: opt.alt || []
});
this.__cache__ = null;
};
/**
* Ruler.after(afterName, ruleName, fn [, options])
* - afterName (String): new rule will be added after this one.
* - ruleName (String): name of added rule.
* - fn (Function): rule function.
* - options (Object): rule options (not mandatory).
*
* Add new rule to chain after one with given name. See also
* [[Ruler.before]], [[Ruler.push]].
*
* ##### Options:
*
* - __alt__ - array with names of "alternate" chains.
*
* ##### Example
*
* ```javascript
* var md = require('markdown-it')();
*
* md.inline.ruler.after('text', 'my_rule', function replace(state) {
* //...
* });
* ```
**/
Ruler.prototype.after = function (afterName, ruleName, fn, options) {
var index = this.__find__(afterName);
var opt = options || {};
if (index === -1) { throw new Error('Parser rule not found: ' + afterName); }
this.__rules__.splice(index + 1, 0, {
name: ruleName,
enabled: true,
fn: fn,
alt: opt.alt || []
});
this.__cache__ = null;
};
/**
* Ruler.push(ruleName, fn [, options])
* - ruleName (String): name of added rule.
* - fn (Function): rule function.
* - options (Object): rule options (not mandatory).
*
* Push new rule to the end of chain. See also
* [[Ruler.before]], [[Ruler.after]].
*
* ##### Options:
*
* - __alt__ - array with names of "alternate" chains.
*
* ##### Example
*
* ```javascript
* var md = require('markdown-it')();
*
* md.core.ruler.push('my_rule', function replace(state) {
* //...
* });
* ```
**/
Ruler.prototype.push = function (ruleName, fn, options) {
var opt = options || {};
this.__rules__.push({
name: ruleName,
enabled: true,
fn: fn,
alt: opt.alt || []
});
this.__cache__ = null;
};
/**
* Ruler.enable(list [, ignoreInvalid]) -> Array
* - list (String|Array): list of rule names to enable.
* - ignoreInvalid (Boolean): set `true` to ignore errors when rule not found.
*
* Enable rules with given names. If any rule name not found - throw Error.
* Errors can be disabled by second param.
*
* Returns list of found rule names (if no exception happened).
*
* See also [[Ruler.disable]], [[Ruler.enableOnly]].
**/
Ruler.prototype.enable = function (list, ignoreInvalid) {
if (!Array.isArray(list)) { list = [ list ]; }
var result = [];
// Search by name and enable
list.forEach(function (name) {
var idx = this.__find__(name);
if (idx < 0) {
if (ignoreInvalid) { return; }
throw new Error('Rules manager: invalid rule name ' + name);
}
this.__rules__[idx].enabled = true;
result.push(name);
}, this);
this.__cache__ = null;
return result;
};
/**
* Ruler.enableOnly(list [, ignoreInvalid])
* - list (String|Array): list of rule names to enable (whitelist).
* - ignoreInvalid (Boolean): set `true` to ignore errors when rule not found.
*
* Enable rules with given names, and disable everything else. If any rule name
* not found - throw Error. Errors can be disabled by second param.
*
* See also [[Ruler.disable]], [[Ruler.enable]].
**/
Ruler.prototype.enableOnly = function (list, ignoreInvalid) {
if (!Array.isArray(list)) { list = [ list ]; }
this.__rules__.forEach(function (rule) { rule.enabled = false; });
this.enable(list, ignoreInvalid);
};
/**
* Ruler.disable(list [, ignoreInvalid]) -> Array
* - list (String|Array): list of rule names to disable.
* - ignoreInvalid (Boolean): set `true` to ignore errors when rule not found.
*
* Disable rules with given names. If any rule name not found - throw Error.
* Errors can be disabled by second param.
*
* Returns list of found rule names (if no exception happened).
*
* See also [[Ruler.enable]], [[Ruler.enableOnly]].
**/
Ruler.prototype.disable = function (list, ignoreInvalid) {
if (!Array.isArray(list)) { list = [ list ]; }
var result = [];
// Search by name and disable
list.forEach(function (name) {
var idx = this.__find__(name);
if (idx < 0) {
if (ignoreInvalid) { return; }
throw new Error('Rules manager: invalid rule name ' + name);
}
this.__rules__[idx].enabled = false;
result.push(name);
}, this);
this.__cache__ = null;
return result;
};
/**
* Ruler.getRules(chainName) -> Array
*
* Return array of active functions (rules) for given chain name. It analyzes
* rules configuration, compiles caches if not exists and returns result.
*
* Default chain name is `''` (empty string). It can't be skipped. That's
* done intentionally, to keep signature monomorphic for high speed.
**/
Ruler.prototype.getRules = function (chainName) {
if (this.__cache__ === null) {
this.__compile__();
}
// Chain can be empty, if rules disabled. But we still have to return Array.
return this.__cache__[chainName] || [];
};
module.exports = Ruler;